> ## Documentation Index
> Fetch the complete documentation index at: https://docs.abbyy.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Component compatibility problems

> Resolve compatibility problems between ABBYY FlexiCapture components, covering database creation, deadlocks, email notifications, and server issues.

This section covers compatibility problems between the Licensing Server, the Processing Server, and the user stations, as well as Single Sign-On (SSO) and encrypted-connection (HTTPS) issues with the Application Server.

<CardGroup cols={2}>
  <Card title="Database creation problems" icon="database" href="/flexi-capture/troubleshooting-guide/tg-communication-data-base">
    The "Access Denied" error, missing connection strings, and Oracle database failures.
  </Card>

  <Card title="Database deadlocks" icon="lock" href="/flexi-capture/troubleshooting-guide/tg-communication-dead-lock">
    Log and analyze SQL deadlocks with Extended Events sessions.
  </Card>

  <Card title="Problems with sending email notifications" icon="envelope" href="/flexi-capture/troubleshooting-guide/tg-communication-mail-notifications">
    Notifications are not sent — check SMTP settings, the MessageQueue table, and the Processing Server.
  </Card>

  <Card title="Application Server performance diagnostics" icon="server" href="/flexi-capture/troubleshooting-guide/tg-communication-application-server">
    Verify the Application Server via IIS pages and the WSDL endpoint, and enable failed request tracing.
  </Card>

  <Card title="Licensing Server problems" icon="key" href="/flexi-capture/troubleshooting-guide/tg-communication-licensing-sever">
    Launch the Licensing Service manually for diagnostics and fix the "RPC Service is not available" error on port 3020.
  </Card>

  <Card title="Processing Server problems" icon="gears" href="/flexi-capture/troubleshooting-guide/tg-communication-proccessing-server">
    The Processing Server cannot launch or stops periodically.
  </Card>

  <Card title="Processing Station problems" icon="microchip" href="/flexi-capture/troubleshooting-guide/tg-communication-proccessing-station">
    A Processing Station cannot be added or launched.
  </Card>

  <Card title="Enable detailed error responses in IIS" icon="triangle-exclamation" href="/flexi-capture/troubleshooting-guide/tg-communication-detailed-errors">
    Turn on detailed HTTP error responses in IIS Manager or web.config.
  </Card>
</CardGroup>